<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8" />
        <meta name="viewport" content="width=device-width, initial-scale=1.0" />
        <title>Document</title>
        <style>
            * {
                margin: 0;
                padding: 0;
                list-style: none;
            }
            body {
                padding: 100px;
            }
            ul {
                display: flex;
                padding: 4px;
                border: 1px solid #000;
            }
            li {
                width: 40px;
                height: 40px;
                margin-right: 10px;
                background-color: red;
                text-align: center;
                line-height: 40px;
            }
        </style>
    </head>
    <body>
        <ul>
            <li>1</li>
            <li>2</li>
            <li>3</li>
        </ul>
    </body>
</html>
